Machine for operating upon hides, skins, leather, and other sheet material



Feb. 24, 1942. E. E. WINKLEY 2,274,114

' MACHINE FOR OPERATING UPON HIDES, SKINS,

LEATHER, AND OTHER SHEET MATERIAL Filed Sept. 5, 1940 v 3 Sheets-Sheet 1Feb. 24, 1942. w Y 2,274,114

MACHINE FOR OPERATING UPON HIDES, SKINS,

LEATHER, AND OTHER SHEET MATERIAL Filed Sept. 5, 1940 3 Sheets-Sheet 2E. E. WINKLEY 2,274,114

MACHINE FOR OPERATING UPON HIDES SKINS,

LEATHER, AND OTHER SHEET MATERIAL Filed Sept. 5, 1940 5 Sheets-Sheet 3Feb. 24, 1942.

""IIIIIIIIIIJJ'III.VII

Patented Feb. 24, 1942 s PAT MACHINE FO RW OPERATING UPON HIDES, SKINS,LEATHER, AND OTHER SHEET MATERIAL Erastus E. Winkley, Lynn, Mass.,assignor to United Shoe Machinery Corporation, Flemington, N. .1., acorporation of New Jersey f Application September 5, 1940, Serial No.355,502

50 Claims. (01449-471 This invention relates tomachines for operatingupon hides, skins, leather, and other sheet material. While theinvention isillustrated as embodied in a machine for operating a glazingtool back and forth over a tanned hideor skin, it isto be understoodthat the invention and various important features thereof may have otherapplications and uses.

i In commercial glazingmachines', as heretofore constructed, the glazingtool has been carried back and forth over a work piece by a lever mov-'-ing as a pendulum while the work piece rests upon a flat surface. Insuch an arrangement the stroke of the lever has been/constantly throughthe same length of arc irrespective of the dimensions of thework piece.Also,'in certain types of leather brushing, rolling, stoning, andwhitening machines, the tool is moved back and forth a fixed distanceirrespective of' the linear dimensions of thework pieces; "Hence, muchof the operative stroke of these different tools is wasted where thework piece -is so idimen- -sioned and positioned that the travelof thetool thereon is short, while in other cases the entire stroke of thetool'produces its efiect on the work piece. From the very nature oftheswinging movement of the tool; in the pendulum type of machines, itmoves'at a faster rate incertain parts ofthe arc than in other parts.Thislack of uniformity in the rate of travel of. the tool over thesurface of the work piece is not con-'- ductive to uniform results.Furthermore, in glazing machines of prior constructions no verysatisfactory provision has been made to secure in. glazing operations apressure suited to variations in the thickness work piece. e n

It is an object of this invention so to control a .35 dimensions of themeans for shifting the work piece between the strokes of an oscillatingor reciprocating tool.

Accordingly,:it is an important feature of the invention that the strokeof a'work treating tool is controlled with reference to a lineardimension of the work piece in the direction of travel of the toolsothat the tool may promptly return for a succeeding work treatingstroke.An advantage of this construction resides in the fact that throughoutthe operative strokes of the tool useful work is performed, whereasheretofore the tool has been carried through a certain definite pathalthough it might be, treating a work piece only through a part of suchpath. For controlling the tool, a detector means-is provided which movesin advance of the tool and controls the tool operating means todetermine the length of the operative stroke of the tool and to reversethe tool promptly when it reachesthe edge oflthe work piece.

Another feature of importance in this invention relates to the provisionof a sensitive means for varying the pressure of ,the Work treatingoperation in accordance with variations in the thickness dimension ofthe work piece in the path of a tool. Conveniently, a feeler membercontacting the work piece in advance of the-tool exercises control of avmechanism for causing relative approaching and separating movementsbetween the tool and a work supporting member. In the illustratedconstruction, the Work support is movable to press the work pieceagainstthe tool and is arranged to be retracted away from the tool whenthinner and morecompressible portions of the work piece are presentedfor treatment, while thicker and denser portions of the work piecereceive heavier pressure during the work treating operation.

work treating tool that the length of'its operative stroke will varyaccording to the dimensions-of the work, piece alongathevarious paths ofthe tool over the surface of the workpiece. It is a further object 'ofthe. invention; to provide a sensitive adjustment of the pressure of awork treating tool with respect to various thicknesses of 1 the workpiece undergoing treatment." Still another object of the invention is toprovide an improved machine in which the tool will travel at auniformrate during the operative stroke thereof, thereby contributingtoxuniformity in the eifiects obtained. Whereas, in'most machines nowinvuse 'inthe tanneries, the work piece has to'be manipulated by theoperator to secure treatment} of successive portions therein, it 'is anobject of this invention to provide-special -Another important featureof the invention resides in the provision of means for shifting a Workpiecebetween operations of a work treating tool, a preferredconstruction being that in which the work shifting means also .places .aportion of the work piece under tension wherein it is held during agiven work treating operation operations upon various parts of the workpiece.

These and other important features of the invention and novelcombinations of parts will now be described in detail in thespecification and then pointed out more particularly in the appendedclaims.

In the drawings,

Fig. 1 is a view in side elevation and partly in section of a glazingmachine illustrating one embodiment of the invention;

Fig. 2 is a front view of the machine shown in Fig. 1;

Fig. 3 is a plan View looking down from above on the machine shown inFigs. 1 and 2; and

Fig. 4 is a detail view of a valve mechanism utilized in the control ofthe hydraulic pistons of the machine.

In the illustrated machine, which is specially designed to performglazing operations upon tanned hides andskins, there isprovided a table6 for supporting a work piece while it. is being treated by a, glazingtool 8 (Fig. 1). The tool 8 is a glass roll of the type well known. incommercial glazing machines. As shown, it is firmly clamped againstrotation, by av clamping member I0, fixed to the forward end of ahead orcarrier H which is-slidable in the frame I2 of the machine ondove-tailedguideways best. shown at I4 in Fig. 2.

For controlling the length of the operative stroke of the tool 8, theillustrated machine is provided with novel detector means comprising, inthe construction shown, a feeler member H3 at the forward end of a leverI 8- pivoted at 2!! on the head or carrier II. As shown, the feeler I6is a forked member, the forward ends of which are substantially inalinementwith a plane passing vertically through the axis of the tool 8.At its rear end the lever I 6 is provided with a roll 22 which ridesalong the upper surface of a controller member 24 yieldingly supportedby a spring 25 and carried by the upper end of a rod 26 slidablevertically in suitable bearings 2'I'i'n the frame of the machine) Whenthe feeler or detector member I6 drops off an edge of the work pieceduring movement of the tool 8 and of the head II' to the right in Fig.1, means (hereinafter described) is operated to terminate the operativestroke of ,the tool as soon as it reaches an edge of the work piece andto return the tool idly for a succeeding stroke across the surface ofthe work piece.

For operating the tool 8 at a uniform rate in its operative stroke, Ihave provided hydraulic means comprising a rack member 36' arranged tobe reciprocated by piston heads 3!, 33 at opposite ends of the member36. While, for cheapness of construction, the heads or pistons 3|, 33are shown as made separate from the member 36, they may be made integraltherewith. In any case, the member 30 with the heads 31, 33 may beregarded as a piston member or device having a rack portion 32 tooperate the tool 8. As shown, the rack 32 is arranged to be constantlyin mesh with a segmental rack 34 secured to a shaft 361 rotatable inbearings in a stationary oil-tight casing member 38 secured to the frame'of the machine- Secured to the end of the shaft 36 outside of thecasing is a lever 46 which at its upper end is pivotally connected at 42to a link 44 which is pivotally connected at its forward end to. thehead or carrier II]. by the pivot pin 20. When the rack member 30. isreciprocated back and forth in its casing 50, the lever 46 is rocked tocause corresponding reciprocatory movement of the head or carrier I Iand hence of the glazing tool 8. During the operative stroke of the tool8 to the right in Fig. 1 it operates on a work piece on the table 6while, during the return stroke of the tool to the left, the table 6 isdepressed, by means hereinafter described, to prevent engagement of thetool with the work during its return stroke, the table 6 being movedupwardly into its elevated or operative position just prior to thebeginning of the next operative stroke of the tool. For reciprocatingthe rack member 38,. hydraulic medium under pressure is admittedalternately to piston cylinder heads 52, 54 through pipes 56, 58,respectively, opening through ports in the cylinders 52 and 54,respectively. The other ends of the pipes 56 and 58 open into a chamberof a valve mechanism 66 which receives pressure medium, such as oilunder pressure, from a pump 62 through a pipe 64 which opens into thevalve chamber 60 through a port located at'a middle part of thelength-of the valve chamber, the pump being driven by anywell-knownpower means such as a motor 6 I.

As shown most clearly in Fig. 4 of the drawings, the valve chamber hasslidably mounted therein a hollow valve member 66 having a middleportion of reduced diameter so that liquid medium entering through thepipe 54 may pass in either direction to the ends of the chamber and. outalternately through either of the pipes 56 and 58, depending upon theposition of the movable valve member 66. When the valve member 66ismoved to the left in Figs. 1 and 4, the pressure medium flows throughpipe 56 to the cylinder 52 and causes movement ofthe rack member to theright during which the liquid flows from thehead 54 through. the pipe58. to the valve casing of valve 66 andinto the hollow movable valvemember 66 and thence out through apipe' 68' to a sump 16. Upon movementof valve member 66 to the right, the liquid flows from pipe 64 to pipe58 and moves the member 36in the reverse direction i. e., to the left,during which the pressure liquid escapes from cylinder 52 through thepipe 56. .to the sump pipe 68. It is to be noted that the valve member66 when inits central position (Fig. 4) covers the openings of the pipes56 and. 58 and that the least movement of the member 66 to the rightpermits liquid to pass from pipe 64 to and through pipe 58, while anequally small movement of 'the valve member 66 to the left directsliquid under pressure from pipe 64 to the pipe 56. The result is asensitivity of valve action that produces instantaneous action in thehydraulically operated members.

hen a piece of work on the table 6. is up intofirm contact with theglazing 531 through the elevation of said table, the feeler or detectormember I6 is lifted by the. work piece with the result that the rear endof the lever I8 is depressed, thereby effecting downward movement of thecontroller member 24 and of the rod 26 secured to its lower surface.Downward movement of the rod 26 has the effect of rockmg a bell cranklever M (Fig. l) in a clockwise direction. Since the upper end of thelever 14 is connected to a valve rod or stem 76 by means of acollar l8slidable on the rod 76 against the tension of a spring 86' it follows tlv iat downw movement of the rod 26* is accompanied by moi ment of therod 76' and of the connected valve member 66 to the rig-ht in- Fig. 1,with the result member 66 fully to the right in Fig, 1, and that thickerwork parts will simply compress the spring 80 further, withoutoscillating the valve member 66. To limit movement of the valve to theright, and to prevent overthrow of member 66 there is provided a stopmember -8I adjustable toward the adjacent end of the piston rod I6. Onthe other hand, when the feeler I6 drops off an edge of thework piece,the controller member 24 rises under the action of the spring 25 withthe result that the bell crank I4, piston rod or stem I6 and valvemember 66 move to the left (Fig. 1) whereby the hydraulic medium underpressure passes through the pipe 56 to the cylinder head 52 to effectinstantly movement of the rack member or piston 30 to the right therebycausing the return or idle stroke of the glazing tool 8. Is should benoted in this connection that spring 80 (Fig. 1) holds the slidablecollar I8 against a stop collar 82 pinned to the valve stem 16. Duringthis return stroke of the tool, the work support 6 is lowered with theresult that the tool does not operate on the work piece. Furthermore,the tool 8 remains at the left end of its stroke while the machine is inrest position, as shown in Fig. 1.

Hydraulic means is also provided for operating the work support in timedrelation to the glazing tool. In the illustrated construction, suchhydraulic means comprises a valve mechanism 90 similar in all respectsto the valve mechanism 60. Fluid under pressure travels from theconstantly operating pump '62 to the valve mechanism 90 through the pipe64 and branch pipe 92, the latter entering the middl portion of thevalve chamber and being directed therefrom through a pipe 94 to acylinder head 96 whereby a piston 91 is instantly forced to the left(Fig. l) to operate rack member 98. As in the case of the tool-operatingpiston 30, the rack member 98 is provided with rack teeth which areconstantly in mesh with the segmental gear I00 secured to a shaft I02journaled in an oil-tight stationary casing I04. To an end of the shaftI02 outside of the casing is secured the lever arm I08 which is forkedto embrace a collar IIO slidable on a post I I2 to the upper end ofwhich is secured the work support 6. Interposed between the collar H0and an enlarged part II4 of the post H2 is a heavy spring I I6. When thecollar IIO, which is engaged by pins carried by the lever arm I08, islifted by said lever arm the spring II6 is compressed and forcedupwardly to effect upward movement of the post I I2 and hence of thetable 6. In other words, the spring H6 serves as the actual pressuremeans by which the work piece is supported against the thrust of thetool 8. This same lever arm I08 is provided with pins I20 which engagein a slot I22 of a sleeve member I24 slidable on a second post I26,upward movement of the sleeve I24 having the effect of compressing alight spring I21 to effect upward movement of a work clamping and movingmeans which will be hereinafter described in detail.

As pointed out above, movement of the rack or piston member 98 to theleft in Fig. 1 results in upward movement of. the work support 6 intocooperative relation with respect to the glazing tool 8. At the end ofthe upward movement of the work support 6, the feeler member I6 islifted just before the work piece contacts the tool 8. Such lifting ofthe feeler member I6 results in downward movement of the controller 24whereby an operative stroke of the tool 8 is initiated. As heretoforepointed out, the feeler I6 travels with the tool 8 in its operativestroke and reaches the edge of the work substantially at the same timeas the tool, so that it drops off said edge of the work and initiatesthe return stroke of the tool as soon as the latter drops off the edgeof the Work, this practically instantaneous response of the hydraulicmeans to the position of the feeler I6 being due to the extremesensitivity of the valve mechanism 60. During this return stroke of thetool the table 6 is depressed, this result being attained throughcontrol of the valve mechanism 90 by the feeler I6. As soon as saidfeeler drops off the edge of the Work, the controller member 24 islifted by the spring 25 with the result that a link I pivoted at I3I tothe lower end of the rod 26 is moved upwardly about a pivot I32stationary at that time. This upward movement of the link I30 has theeffect of lifting a valve rod or stem I36 (connected to the link I30 bya pin I33 secured to the link I30 and operating in a grooved spool I35)slidable on the valve stem I36 thereby shifting the valve member insideof the valve chamber 90 in a direction to cause the pressure medium tomove through the valve mechanism to a pipe I40 opening at its other endinto a piston cylinder head I42 whereby the rack member or piston 98 isinstantly operated in the reverse direction, that is, to the right inFig. 1, whereby the work support 6 is lowered and with it the workclamping devices. It is pointed out that the spool I35 is yieldinglyheld against a collar I 31 pinned to the end of the valve stem I36 by aspring I39. At its other end, the spring I3'I presses against a blockI59 fastened to the stem I36. During the interval that the work support6 is lowered, the tool 8 returns to its extreme left position in Fig. 1in its idle stroke.

While the valvemechanism controls the rack member or piston 98 foreffecting movement of the work support 6 between work receiving and workpresenting positions with respect tothe tool 8, the said valve mechanism90 and the member 98 are also controlled in such manner as to vary thepressure with which a given work piece is pressed against the tool 8during the operative stroke of the latter. It will be noted that thefeeler member I6 is located closely adjacent to the tool 8. As ittravels over the surface of the work piece with the tool 8 it respondsto variations in the thickness dimension of the work piece in its pathover the latter. The result is that the controller member 24 movesslightly in up-and-down directions corresponding to the movements of thefeeler I6. Hence the hollow valve member in the valve mechanism 90 isshifted accordingly and thereby varies the flow of liquid under pressurethrough the pipe 94 to the piston cylinder 96 and hence varies thepressure by which the work support 6 presents the work piece against thetool 8.

When, for instance, a thin spot is contacted by the feeler I6, thecontroller membr 24 is lifted by the spring 25, with the result thatlink I30 is lifted about pivot I32, whereby valve stem I36 is movedupwardly together with the valve member in valve 66. Hence liquid flowsthrough pipe I40 to the cylinder head I42, thereby moving rack member 98to the right a, slight amount, causing downward movement of lever armI08 and hence of. the work support 6. But a link I4I pivoted to leverarm Ii58-is also pivoted at'its other end to a lever I43 pivoted at I45to the frame of themachine. The free end of lever I43 is pivoted to alink I I-1* pivoted on pivot pin I32 of link I35. Hence any downwardmovement of lever arm I68 and of the work support 6. will cause loweringof the valve stem I36 and hence of the movable valve member in valve 96which is thus, returned to neutral position. In other words, the rackmember 98 is hydraulically lock in the new position which puts a littleless pressure on the spring II6 which supports and delivers thenecessary pressure on the leather. By varying the tension of the springII6 hydraulically, pressure on the work piece is varied in accordancewith the thickness dimensions thereof. When feeler I6 dropped lowerbecause of a thin spot, rod 26 moved upwardly and link L36 turned aboutI32 as a pivot to lift valve member in valve 96., thereby permittingflow of pressure medium through pipe M6 to lower the lever arm I06 andwork support 6. But lowering of. arm I68 lowers lever I43 about pivotI45, thereby lowering; link I88 about pivot I3I which had been liftedwhen feeler I6 engaged the low spot. Hence link I66.- rocks about pin-I-3I and brings valvemember in valve 90 to neutral position with thepiston 63 hydraulically locked against movement, thus maintaining upwardpressure on spring Mo tosupport the table 6. This mechanism affords avery sensitive adjustment of the glazing tool to variations in thethickness dimension of the work piece in the path of the feeler andtool. In the illustrated construction, this pressure is slightly lessfor thinner portions of the work piece than it is for thicker portionsthereof.

As a safety feature, for instance, if the operator does not center askin properly, or if a skin is toolarge for the machine, the feeler [-6may not drop downwardly at the end of its. stroke to the right. However,it is necessary to-reverse the stroke and to lower the table, otherwisethe machine would be locked against further operation. Hence a link I!is pivoted to the lever 46 and to a bell-crank I53 through a slottedpart I55of link I-5I the latter permitting a normal stroke of the tool 8and feeler I6, after which the shoulder at the left end of the slot I55will operate the bell crank I56. Operation of bell crank I53 lifts alink I53apivoted at its lower end to a block I59 fixedly secured to thestem I66 of the movable valve in the valvedevice 66.. Lifting of thevalve member in valve- 96 sends liquid through pipe I46 and effectslowering of the work support, thus conditioning the machine for asucceeding operation.

As heretofore indicated, the illustrated machine preferably embodieswork clamping and moving means, the purpose being to shift the workpiece after each operative stroke of the glazing tool 8. This makes themachine automatic in itsoperations on a given piece of work,

whereas heretofore the operator had to shift the work piece betweensuccessive strokes of the operating tool. In the illustratedconstruction, the work clamping means comprises work clamping membersI56, I52 (Fig, 2) carried by hubs I54 and I56, respectively, the saidhubs being rotatably mounted upon the upper end of the post I26 and heldagainst movement lengthwise of the post I 26- by collars I51. A springI58. is connected to pins on both of the members I50, I52 to hold thesemembers yieldingly toward each other. For co-operation with the workclamping members I56, I52 which are movable upwardly with the post I26,there is provided a pair of work clamping members I66, I62 carried byhubs I64- and I66, respectively, the said hubs being rotatable on avertical stub shaft I 68 but being restrained against up-and-downmovement. The work clamping members I60, I62 have connected therewith aspring III] which holds the members I 66, I 62 yieldingly toward eachother.

It will be readily understood that the Work clamping members I50, I52move upwardly and co-operate with the work clamping member I66, I62 wellbefore the work support 6 presents the work piece to the tool 8. Infact, means is provided for rotating the work clamping members afterthey engage the work piece so as to shift .the latter over the surfaceof the work support 6 to present another portion thereof for the nextstroke of the tool. At the end of the sidewise swinging movement of thework clamping members I56, I52 and I66, I62, the latter are operated toseparate or recede laterally from each other so as to place that portionof the work piece between them under tension while the tool isoperating. The means for accomplishing these operations will now bedescribed.

As shown most clearly in Fig. 2, the hub I56 of the work clamping memberI52 has a projecting ear III thereon to which is connected a link I86having an opening in its, outer end for the reception of an upstandingpin I82 secured to the end of a link member I84 pivoted at the forwardend of a slide member I85 (Figs. 1 and 2). By having the pin I82 ofsubstantial length, the connection between the link I80 and the linkmember I84 is maintained at all times, that is, during upward anddownward movement of the work clamping members on the post I26. Movementof the link member I84 to the rear in Fig. 1 will result in swinging thework clamping members in a clockwise direction (Fig. 3) to shift thework piece over the upper surface of the work support 6. This operationof the work clamping members I50, I52 will be better understood uponreading the following description of the clamping members I69, I62 whichare also shown more clearly in the plan view of Fig. 3. In order thatthe upper work clamping members I66 and I62 may be positively rotated atthe same time as the lower clamping members, the hub I66 of the workclamping member I62 is provided with an ear I186 (Figs. 2 and 3) towhich is pivoted a link I81 in turn pivoted to the forward end of a linkmember I at the forward end of a slide member I91. Similarly, hub I64(Fig. 2) has an ear I93 (Figs. 2 and 3) to which is pivoted a link I95pivoted at its other end to lever I8'I. These slide members I85 and I9Iare moved rearwardly in Figs. 2 and 3 to rotate the work clampingmembers after they have engaged the work piece. At the end of thisswinging or rotating movement of the work clamping members, terminatedby the upper member I52 coming into contact with a side edge of thetable 6 (Fig. 3), they are caused to move away from each other in setsupon opposite sides of the table 6 to tension a portion of the workpiece between them so that the work pieceis properly conditionedv fortreatment by the glazing tool 8.

on the sleeve I24 until The described separating movement of the sets ofwork clamping members is accomplished through the operation of a levermechanism most clearly shown in Fig. 3. Upon reference to Fig. 3 it willbeobserved that the ear I86 on the hub I66 is movable about the shaftI68 and has pivoted Ito its end a lever member I81 to which is pivotedthe short link I95 also pivoted to an ear I93 rigid with the hub I64 ofthe work clamping member I60. It will be clear that clockwis rotation ofthe lever I81 in Fig. 3 will result in straightening a toggle of whichthe link member I95 is the other member, the straightening of the togglebeing accompanied by separrating movement of the work clamping membersI60, I62 to tension a portion of the work piece. It is to be understoodthat the lower work clamping members I50, I52-are operated in the samevivay simultaneously with the upper members I60,

For operating the work clamping devices after they have engaged the workpiece, there is preferably provided a hydraulic mechanism similar tothat for operating the tool 8 and to that for operating the work support6. This hydraulic mechanism comprises a valve mechanism 220 (Fig. 1)which is similar in all respects to the valve mechanisms 60 and 90. Inthis case, fluid under pressure comes from the pump 62 by a pipe 222 anda branch pipe 224 opening into-the middle part of the valve casing ofvalve mechanism 220. The movable valve member inside the casing iscontrolled by a valve stem 226 having at its outer .end a roller 228 incontact with a flat surface 230 on the sleeve I24. When the sleeve I24is moved upwardly by the lever arm I08, the roller 228 rides along theflat. surface 230 and also along a flat surface of a latch member 232.When the roller 228 drops off the lower end of the surface of the latchmember 232, the valve stem 226 is projected to the left (Fig. l) by aspring 234. This movement of the valve stem and movable valve memberinside 220 results in passage of the pressure medium under pressurethrough a pipe 240 to a piston cylinder 242 (Fig. 3) which contains apiston to operate a rack 243 in casing 244 similar in all respects tothe rack 30 and to the rack 98 of Fig. 1.

In fact, the showing of the piston 38 and all its operating parts inFig. 1 is also a disclosure of the pistonin cylinder 242 and of the rack243 in casing 244. Movement of this piston and rack in the casing 244operates a lever 250 (Fig. 1) which is connected by a link 252 to thepair of slide members I85, I9I which in turn are connected at theirfront ends through links I84 and I90 to the lower and upper workclamping members I52 and. I62, respectively, to operate the latter inthe two successive movements described above. These movements of theclamping members are accomplished before the work support presses thework piece against the tool 8.

There has been described in the preceding paragraph the manner ofoperating the valve stem'226 (Fig. 1) which carries the roller 228,.1tbeing stated that upward. movement of the sleeve I24 on the post I26results finally in the dropping of the roller 228 off of the lower endof a flat surface on the latch member 232. During the subsequentdownward movement of the sleeve up a slanting surface 210 it lifts thespring pressed latch member 232 and reappears on the fiat surface in theposition shown in Fig. 1. It W111 be understood, of course, thatdownward movement I24, the roller 228 runs of the post I26 and of thesleeve I24 is accompanied by downward movement of the lower workclamping members I50, I 52. During this downward movement the valve stem226 is moved to the right, thus effecting a reverse movement of thevalve member in the valve mechanism 220 with the result that pressuremedium under pressure flows out through a pipe 212 whereby such pressuremedium under pressure is introduced into a piston cylinder head 214(Fig. 3) to move the rack 243 in casing 244 in the direction to swingthe work clamping members to their initial positions, in which they areready to clamp a work piece upon a subsequent upward movement of thelower clamping members.

When the machine is at rest, the valve member in valve device is down sothat liquid may enter cylinder head 96 to start lifting of the worksupport 6.. Also valve member 66 in valve device 60 is over to the leftin Fig. 1, while the machine is at rest, to hold the tool 8 over to theleft while table 6 is down and while the latter is rising. Contact ofthe work piece with the feeler I6 starts operation of the tool 8. Alsothe work clamping members are held in the position of Fig. 1 by the rackor piston member 243 under control of the valve 220 as conditioned bythe position of the valve stem 226 and roller 228 (Fig. 1).

To start the machine in operation, the operator steps on a tread portion290 of a treadle shown in Fig. 2 of the drawings with the result that atoggle 292 is broken thereby lowering a spring loaded relief valvemember 294 in a valve chamber 296. Such movement 'of the valve 294 stopsthe flow of liquid through a pipe 300 to the sump 10 with the resultthat liquid from the pump 62 is forced to pass upwardly through thepipes 64 and 224 to the valve mechanisms 60, 90 and 220, respectively,whereby the racks 30, 98 and 243, respectively, are actuated in timedrelation to each other. As soon as the table supporting post II2 movesupwardly following the closing of the valve in valve device 296, a lever3) (Fig. 2) is rocked by a spring 3I2 to project a latch 3I4 into anotch 3I6 in a member 3I8 fixed to the treadle, the result being thatthe treadle is locked with the valve in valve casing 296 in position tomaintain the machine in operation while it is treating a given piece ofwork and until the treadle is moved in the opposite direction by thefoot of the operator it being understood in this connection that thetoggle 292 will remain in broken condition in the brief intervals duringwhich the work support is in lowered position. When the work support isin the lower position the treadle may be moved to the position shown inFig. 2 to straighten the toggle and stop the operation of the machine.The toggle moves beyond center to hold the inoperative position shown inFig. 2.

In operating the illustrated machine to glaze a kid skin, for instance,the latter is placed on the work support 6 with the center point in thebackbone line of the skin directly under the tool 8. As the work supportand lower work clamping members rise toward the tool, the work clampingmembers engage the skin and shift it laterally in the manner describedbefore the work support presses the skin against the tool. Not only isthe skin shifted but it is tensioned by a separating movement of thework clamping members before it is pressed against the tool. As

' the feeler I6 moves upwardly through pressure ates an operative strokeof the tool which is terminated as soon as the tool drops off the edgeof the skin. The tool is then returned in its idle stroke which takesplace while the work support is depressed along with the lower workclamping members. These members then rise again to engage the skin inits new position and to shift and tension it prior to the next workingstroke of the tool. These operations are repeated until all portions ofthe skin have been successively presented for treatment. It is to beunderstood, of course, that a supplemental work support may be providedwhich will be stationary in the plane of the support 6 when the latteris in its raised position, this supplemental work support being of asize to furnish support for those parts of a hide or skin which normallywould extend beyond the support 6, this arrangement insuring that thehide or skin will not be displaced by gravity in the intervals betweenthe work clamping and shifting operations.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent'of the United States is:

1. In a machine for operating on sheet material, a work support, a toolmovable in opposite directions relatively to a work piece on saidsupport, said tool having an operative stroke in one direction and anidle stroke in the opposite direction, means for reciprocating the toolin its idle and operative strokes, and means controlled directly by thework piece with reference to a linear dimension thereof to terminate theoperative stroke of the tool according to the length of said dimension.

2. In a machine for operating on sheet material, a Work support, a toolmovable in opposite directions relatively to a work piece on saidsupport, said tool having an operative stroke in one direction and anidle stroke in the opposite direction, means for reciprocating the toolin its idle and operative strokes, and detector means controlleddirectly by the work piece with reference to a linear dimension thereofto initiate return of the tool in its idle stroke when said tool dropsoff an edge of the work piece.

3. In a machine for operating on sheet material, a work support, a toolmovable in opposite directions relatively to a work piece on saidsupport, said tool having an operative stroke in one direction and anidle stroke in theoppesitedirection, means for reciprocating the tool inits idle and operative strokes, and work-controlled detector meansmovable with the tool to determine the length of the operative stroke ofthe tool whereby the latter is reversed when it passes oif an edgeportion of the workpiece.

4. In a machine for operating upon sheet material, the combinationwith awork support and a tool, of power operated meanssfor imparting to saidtool repeated movements in one direction in operating upon a work pieceon said support, and work-controlled means for terminating eachoperative movement of the tool as soon as "the tool is moved out ofengagement with the work piece.

5. In a machine for operating on sheet material, a work support, a toolfor operating on a work piece, means for reciprocating the tool in itsidle and operative strokes, and Work-controlled detector means spacedfrom said tool in the-direction of its operative-stroke and'movable-therewith to detect the approach of said tool with respect toan edge portion of the work piece and to initiate return of the tool inits idle stroke as soon as the latter drops off the edge of the workpiece.

6. In a machine for operating on sheet material, a work support, a toolfor operating on a work piece, means for reciprocating the tool in itsidle and operative strokes, work-controlled detector means to controlthe operative stroke "of the tool whereby the tool is reversed when thelatter passes off an edge portion of the work piece, and means forcausing relative separating movement of the tool and Work support theinstant the tool drops off said edge portion of the work piece wherebythe return stroke of the tool becomes an idle'stroke.

7. In a machine for operating on sheet material, -a work support, a toolfor-operating on a work piece, means for reciprocating the tool in itsidle and-operative strokes, work-controlled detector means to' controlthe operative stroke of the tool whereby the latter is reversed when itpasses off an edge portion of the work piece irrespective of the lengthof such operative stroke, and means for lowering the work support theinstant-the tool passes on said edge -'of the work piece whereby thereturn stroke of the tool becomes an idle stroke.

8. In a machine for operating on sheet material, a work support, a toolfor operating on a work piece, means for reciprocating the tool in itsidle and operative strokes, detector means directlycontrolle'dby thework piece and operative to control the operative stroke of the toolwhereby the tool is reversed when it passes off an edge portion of thework piece, said reciprocating means including a piston for operatingthe tool inane-direction, and hydraulic means for operating the pistonto move the tool at a uniform rate of travel over the surface of thework piece.

9. In a machine for operating on sheet material, a work support, a toolmovable in a plane above the work support for operating on a work pieceon said support, means for moving the work support toward and from theoperative plane of the tool, detector means directly responsive to thepresence and absence of a work piece on the work support and operativeto control the operative stroke of the "tool, a piston device foroperating the tool, and hydraulic means under the control of saiddetector means for operating the piston device to move the tool at auniform rate of travel over the surface of the work piece.

10. In a machine for operating on sheet material, a work support, a toolmovable in a plane above the work support for operating on a work pieceon said support, means for causing relative approaching and separatingmovements between the work support and tool during movements of the toolin it's operative and idle strokes, detector means directly controlledby the work piece and operative to control'the operative stroke of thetool whereby the tool is reversed when the latter passes off an edgeportion of th work piece, a piston device including a rack for operatingthe 'tool, and hydraulic means under the control of said 'detector meansfor reciprocating the piston device alternatively in oppositedirections, the relative separating movement of the work support andtool being timed to produce the idle 'stroke of the tool with respect tothe workpiece.

11. In a machine for operating on sheet material, a tool,-awork-supportfora workpiece duringtreatment thereof, means for moving thetool back and forth in a plane above the work support, a feeler devicemovable with the tooland piece before the tool reaches such edgeportion, means controlled by the feeler device to reverse the directionof movement of the tool as soon as the tool drops off the edge of thework piece, and means to cause a relative separating movement betweenthe work support and tool during the return movement of the tool so thatsuch return movement is an idle stroke of the tool preparatory to asucceeding operative stroke'thereof.

12. In a machine for operating upon sheet material, a'work support, atool movable over the surface of a work piece on. the 'work support,means for moving said tool back and forth overthe surface of the workpiece, power means for causing relative approaching and separatingmovements of the work support and tool, and detector means operating inadvance of the tool in the direction of its operative stroke to controlthe said power means in accordance with the thickness of the work piecein the path of the tool, whereby the pressure of the tool on the workpiece may be suited to various portions thereof.

13. In a machine for operating upon sheet ma- "terial, a work support, atool, power means to move the tool over the surface of a work piece onthe work support, hydraulic means comprising a valve mechanism forcausing relative appreaching and separating movements between theworksupport and tool, and a feeler device movable in advance of the toolduring its work treating movement and operative to respond to variationsin the thickness of the work piece in the path of the feeler and tool,said feeler device having connections to control said valve mechanismwhereby the pressure between the Work support and the tool is adjustedto the varying thickness of the work piece during movement of the toolover the work piece.

.14. In a machine for operating upon sheet material, a work support, atool movable in a plane above the surface of awork support to operate ona work piece on the support, power means for causing relativeapproaching movement between the work support and tool, power means formoving the tool back and forth in its operative and idle strokes, afeeler device contacting the work piece and movable in advance of thetool in its operative stroke, and connections between the feeler memberand both of said power means whereby the feeler device controls not onlythe length of the operative stroke of the tool but also the pressurebetween the work support and tool in accordance with variations in thethickness of the work piece in the path of the tool.

15. In a machine for operating upon sheet material, a work support, atool for treating a work piece while the latter is backed by thesupport, hydraulic means comprising a piston device have ing operativeconnections with said tool, cylinders for slidably receiving theopposite ends of said device, a valve mechanism to control the passageof pressure medium alternately to said.

cylinders whereby the piston device and the tool are reciprocated, afeeler device contacting the work piece and movable in advance of thetool in thedirection of its operative stroke, and connections betweenthe feeler device and said valve mechanism to control the latter wherebythe piston device and hence the tool are reversed in their direction ofmovement when the feeler drops off an edge of the work piece.

I 16. In arnachine for operating upon sheet material, awork support, atool to operate on a work piece backed by said work support, power meansfor causing relative approaching and sep-,

arating movements between the work support and tool, power means formoving the tool along a given path on the surface of the work piece onthe work support to treat that portion of the work piece in the path ofthe tool, a pair of work clamping members at each side of the Worksupport, one member of each pair being above and the other below theplane of the work piece on said support, thus providing an upper and alower set of work clamping members, means for causing the work clampingmembers to engage a work piece placed between them, and power meansoperating in timed relation to the two first-mentioned power means tomove the pairs of work'clamping members away from each other on oppositesides of the work support to place that portion of the work piece lyingbetween the pairs of members under tension prior to each of theoperative strokes of the tool.

17.- In a machine for operating upon sheet material, a work support, atool movable from a middle portion of a work piece to a margin thereof,power means for reciprocating the tool in its operative and idlestrokes, a pair of work clamping members on each side of the worksupport, one of each pair being above and the other below the worksupporting surface thereof, thus providing an upper and a lower set ofwork clampingmembers, power means for moving one set of work clampingmembers toward the other whereby the work piece is clamped by saidclamping members, means for rotating the clamping members to shift thework piece in one direction over the surface of the work support priorto the operation of the tool, and means for movingthe pairs of clampingmembers on each side of the work support away from each othersufiiciently to place the work piece under tension prior to theoperation of said tool.

18. In a machine for operating upon stretchy sheet material, a worksupport, a tool movable from a middle portion of a work piece to amargin thereof, a pair of work clamping members on each side of the worksupport, one of each pair being above and the other below the worksupporting surface thereof, thus providing an upper and a lower set ofwork clamping members, power means for moving one set of work clampingmembers toward the other whereby the work piece is clamped by saidclamping member, power means for rotating the clamping members to shiftthe work piece in one direction over the surface of the Work supportprior to the operation of the tool, means operating in timed relation tothe rotating means for moving the work support in a direction to pressthe work piece against the tool, means for causing a relative separatingmovement of the pairs of clamping members on each side of the table toplace the ,work piece under tension just prior to the pressing of thework piece against the tool, and means for operating the tool to treatthe work piece while the latter is held under tension by the Workclamping members.

' 19. In a machine for operating upon stretchy sheet material, aworksupport, a tool movable from a middle portion of a work piece to amargin thereon, a pair of work clamping members on each side of the worksupport, one of each pair being above and the other below the worksupporting surface thereof, thus providing an upper and a lower set ofwork clamping members, power means for moving one set of work clampingmembers toward the other whereby the work piece is clamped by saidclamping members, means for rotating the clamping members to shift thework piece in one direction over the .surface of the worksupport prior"to the operation of the tool, power means for moving the work supportin a direction to press the work piece against the tool, means forcausing a separating movement of the pairs of clamping members on eachside of the work support to place the work piece under tension justprior to the pressing of the work piece against the tool, means foroperating the tool to treat the work piece while the latter is held bythe work clamping members, means for lowering the work support and atthe same time returning the work clamping members to their initialpositions whereby the Work piece is released by both the work supportand the work clamping members, the subsequent upward movement of theworksupport and of the lower set of work clamping members beingaccompanied by reengagement of the work piece by the work clampingmembers together with the rotary movement of the work "clamping membersto reposition the work before the succeeding operation of the tool.

20. In a machine for glazing leather, a glazing tool, a Work supportmovable to back a work piece against the thrust of the tool, means formoving the tool back and forth in a plane above the work support, afeeler device movable with the tool and arranged to drop off an edgeportion of the work piece before the tool reaches such edge portion,means controlled by the feeler member to reverse the direction ofmovement of the tool as soon as the latter drops off the edge of thework piece, and means to retract the work support during the returnmovement of the tool so that such return movement is an idle stroke ofthe tool preparatory to a succeeding operative stroke thereof.

21. In a machine for operating upon hides and skins, a work support, atool movable over the surface of a work piece on the work support, powermeans for reciprocating said tool back and forth in a plane above thesurface of the work support, means for moving the work support towardand from the tool, and a feeler device contacting the work piece inadvance of the tool in the direction of its operative stroke to controlsaid work support moving means in accordance with the thickness of thework piece in the path of the feelermember and tool.

22. In a machine for operating upon hides and skins, a work support, atool movable over the surface of .a work piece on the work support,power means for reciprocating said tool back and forth in a plane abovethe surface of the work support, hydraulic means comprising a valvemechanism for moving the work support toward and from said tool, and afeeler device movable in advance of the tool during its operative strokeand operative to respond to variations in the thickness of the workpiece in the path of the feeler and tool, said feeler member havingconnections to control said valve mechanism Whereby the work support isadjusted to the varying thickness of the work piece during the movementof the tool in its operative stroke.

23. In a machine for treating hides and skins, a work support, a toolmovable in a plane above the surface of a work support to operate on a.

work piece on the support, power means for moving the Work supporttoward and from said plane, power means for moving the tool back andforth in its operative and idle strokes, a feeler device contacting thework piece and movable in advance of the tool in its operative stroke,and connections between the feeler device and both of said power meanswhereby the feeler member controls not only the length of the operativestroke of the tool but also the position of the work support inaccordance with variations in the thickness of the work piece in thepath of the tool over the latter.

24. In a machine for operating upon hides and skins, a work support, atool for treating a work piece while the latter is backed by thesupport, hydraulic means comprising a piston device having operativeconnections with said tool, cylinders for slidably receiving theopposite ends of said piston device, a valve mechanism to control thepassage of pressure medium alternately to saidcylinders, whereby thepiston device and the tool are reciprocated, a feeler device contactingthe work piece and movable in advance of the tool in the direction ofits operative stroke, connections between the feeler device and saidvalve mechanism to control the latter whereby the piston device andhence the tool are reversed in their direction of movement when thefeeler drops off an edge of the work piece, hydraulic mechanism to movethe work support toward and from the tool, and connections between saidfeeler member and the hydraulic mechanism to control the movement of thework support in accordance with the thickness of the work piece in thepath of the feeler member. W

25. In a machine for operating upon hides and skins, a work support, atool movable from a middle, portion of a work piece to a margin thereof,hydraulic means for reciprocating the tool in its operative and idlestrokes, a pair of work clamping members on each side of the worksupport, one of each pair being above and the other below the worksupporting surface thereof, thus providing an upper and a lower set ofclamping members, power means for moving one set of work clampingmembers toward the other whereby the work piece is clamped by saidclamping member, and hydraulic mechanism operating in timed relation tothe hydraulic means to move the clamping members to shift the work piecein one direction over the surface of the work support prior to theoperation of the tool.

26. In a machine for operating upon hides and skins, a work support, atool movable from a middle portion of a work piece to a margin thereof,hydraulic means for reciprocating the tool in its operative and idlestrokes, a pair of work clamping members on each side of the worksupport, one of each pair being above and the other below the worksupporting surface thereof, thus providing an upper and a lower set ofclamping members, power means for moving one set of work clampingmembers toward the other whereby the work piece is clamped by saidclamping members, means to move the clamping members to shift the workpiece in one direction over the surface of the work support prior to theoperation of the tool, and hydraulically operated mechanism operating intimed relation to said bydraulic means to move the clamping members oneach side of the work support away from each other sufficiently to placethe work piece under tension prior to the operation of said tool.

27. In a machine for operating upon hides and sk ns, a work support, atool movable from a middle portion of a work piece to a margintheremembers, means to move the clamping members to shift the work piecein one direction over the surface of the work support prior to theoperation of the tool, hydraulic mechanism operating in timed relationto said hydraulic means for causing relative approaching and separatingmovements between the work support and tool in a direction to press thework piece against the tool, and means for causing a separating movementof the clamping members on each side of the table to place the workpiece under tension just prior to the pressing of the work piece againstthe tool, the meansfor operating the tool being operative while the workpiece is held by the work clamping members.

28. In a machine for operating upon hides and skins, a work support, atool movable from a middle portion of a work piece to a margin thereon,hydraulic means for reciprocating the tool in its operative and idlestrokes, a pair of work clamping members on each side of the worksupport, one of each pair being above and the other below the worksupporting surface thereof, thus providing an upper and a lower set ofclamping members, hydraulic means for moving one set of work clampingmembers toward the other whereby the work piece is clamped by'saidclamptimed relation to the two hydraulic means above mentioned forcausing a separating movement of the clamping members on each side ofthe table to place the work piece under tension just prior to theoperation of the tool, said means for operating the tool being operativeto treat the work piece while it is held under tension by the workclamping members, and means for lowering the work support and at thesame time returning the work clamping members to their. initialpositions, whereby the Work piece is released by both ing members, meansfor moving the clamping 4 members to shift the work piece inonedirection over the surface of the work support prior to the operationof the tool, the work support being movable in a direction to press theworkpiece against the tool, hydraulic means operating in the worksupport and the work clamping members, the subsequent upward movement ofthe 7 work support and of the lower set of the work clamping membersbeing accompanied by reengagement of the work piece by the work clampingmembers together with a rotary movement of the work clamping members toreposition the work before the succeeding operation of the tool.

29. In a machine for operating upon sheet material, the combination witha work support and a tool, of power operated means for imparting to saidtool repeated baok-and-forth' movements in operating upon a work pieceon said support, and work-controlled means for reversing that movementof the tool which ends with the latter dropping off the edge of the'workpiece, said work-controlled means becoming operative to reverse the toolas soon as the latter drops off the Work piece.

30. In a machine for operating on sheet material, a tool, a Work supportfor .a work piece during treatment thereof, means for moving the toolback and forth in a plane above the work support, a feeler devicemovable with the tool and arranged to drop off an edge portion of thework piece before thetool reaches such edge portion, and meanscontrolled bythe feeler device to reverse the direction of movement ofthe tool as soon as the tool drops oif the edge of the work piece.

ERASTUS E; WINKLEY.

